On February 3, 2023, a train carrying hazardous chemicals derailed in East Palestine, Ohio. Initial mobile air monitoring in mid-February 2023 revealed unique spatiotemporal patterns for a range of volatile organic compounds (VOCs). To determine long-term impacts on air quality, two follow up mobile air monitoring campaigns were carried out in March and April 2023 on public roadways using a proton transfer reaction time-of-flight mass spectrometer. This study aimed to characterize VOC distributions, identify hotspots, and characterize potential hazards. Concentrations of targeted VOCs benzene, toluene, and xylenes were lower overall in East Palestine in April compared to March. Overall, more compounds (n = 48) were identified using non-targeted analysis (NTA) in East Palestine in March compared with April (n = 30). Several of these VOCs were uniquely identified during March sampling, and among the commonly detected compounds, higher average concentrations were observed in East Palestine compared background levels. Spatial analysis revealed similar patterns of hotspots for benzene and additional VOCs identified from NTA, including C3H4O, C4H8O, and C6H12O. Using the EPA Hazard Comparison Dashboard, 49% and 40% of the identified VOCs were classified as “very high” or “high” hazards for eye and skin irritation, respectively. Notably, eye and skin irritation were among the common symptoms reported by the residents near the disaster site. Additionally, 29%, 18%, and 14% of the identified VOCs were classified as “very high” or “high” hazards for genotoxicity/mutagenicity, acute inhalation toxicity, and acute dermal toxicity, respectively. Collectively, these findings provide exposure data supportive of the reported health concerns and demonstrate the application of mobile monitoring coupled with NTA as a novel approach for rapid identification and mapping of potentially hazardous chemicals following an environmental disaster.
